<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>

    <div class="box">
        <div class="box-arrow"></div>
        <style>
            .box {
                width: 200px;
                height: 50px;
                box-shadow: 0 0 20px rgba(0, 0, 0, .2);
                border: 1px solid #d6d9dc;
                position: relative;
            }

            .box-arrow {

                position: absolute;
                top: 0;
                left: 100%;
                height: 100%;
                overflow: hidden;
                width: 16px;
            }

            .box-arrow::after {
                content: " ";
                position: absolute;
                top: 50%;
                left: -0%;
                width: 16px;
                height: 16px;
                background-color: #fff;
                border: 1px solid #d6d9dc;
                box-shadow: 2px 0 8px rgba(59, 64, 69, 0.1);
                transform: translateY(-50%) translateX(-50%) rotate(45deg);
                transition: all .2s;
            }
        </style>
    </div>

</body>

</html>